Machines that utilize electrical wire in the manufacture of a product typically draw lengths of wire from an endless source, such as a reel, and feed the drawn wire into mechanisms that operate on the wire in some way to produce the product. Sometimes the wire is cut to a specific length and it becomes the product, other times the wire is used to interconnect electrical components in a product. The former, for example, is made by a machine that is typically called a "lead maker" in the industry. These machines draw wire from an endless source, measuring its length precisely, then cutting it to a desired length. The ends may or may not be terminated to electrical terminals, or the ends may simply be prepared for termination. In any case, at the instant that the wire is being operated upon it must be stationary with respect to the operating tooling. Therefore, the feed mechanism must feed the wire in incremental amounts that correspond in length and timing to the operations being performed on the wire. These machines process wire at a rate of up to 450 inches per second and may impart acceleration to the wire of up to 3000 inches per second per second. As the wire is being incrementally fed under these conditions of high speed and high acceleration, the wire reel from which the wire is being drawn can offer significant resistance due to its inertia. This resistance can over stress the wire. Additionally, as the wire is being pulled by the feed unit the wire reel will occasionally begin to rotate too fast so that wire spills out onto the floor faster than it can be picked up by the intermittent wire feed unit. Attempts to alleviate this problem include the rotation of the wire reel in timed relation to the feed unit or a mechanism to absorb the shock of the wire and to store wire slack. The shock absorbing mechanism is now widely used in the industry because rotation of the wire reel is difficult to control without complex equipment. The shock absorbing mechanism usually consists of two horizontally disposed shafts, one vertically above the other. The first shaft is fixed while the second is arranged to move vertically toward or away from the first shaft and is biased in the away direction either by gravity or a spring. Each shaft has several pulleys arranged thereon with the wire threaded around the first pulley on the first shaft then around the first pulley of the second shaft then around the second pulley of the first shaft, and so forth. As the wire exits the last pulley it is threaded into the wire feed unit of the machine. As the feed unit intermittently draws wire, the lower second shaft moves toward the first shaft by the amount required to supply the wire being drawn. When the feed unit pauses the second shaft, being biased away from the first shaft, will tension the wire thereby causing the wire reel to turn. This uncontrolled turning of the wire reel is characterized by alternating fast and slow rotation so that the wire is still stressed at points of the feed cycle and the wire reel may occasionally turn too fast so that slack wire is spilled out onto the floor. These machines usually include a wire marking unit that must be positioned a specific distance away from the feed unit for marking the ends of the wires being processed during null periods of feeding. When the lengths of the wires being processed are quite long, twenty feet for example, the wire marking unit must be placed up to twenty feet away from the machine thereby requiring an inordinate amount of floor space.
What is needed is a wire dereeling unit that draws wire from the wire reel at a constant speed so that the wire reel turns at a more constant speed, while permitting intermittent feeding of the wire by the feed unit. Additionally, the wire marking unit should include wire storage capacity sufficient to permit marking of the wire during null periods of feeding without extending the length of the machine beyond reasonable limits.